Re: scheduler clock for MXS [Was: Re: Wakeup latency measured with SCHED_TRACER depends on HZ]
From: Russell King - ARM Linux <hidden>
Date: 2012-11-06 20:04:45
Also in:
linux-arm-kernel
From: Russell King - ARM Linux <hidden>
Date: 2012-11-06 20:04:45
Also in:
linux-arm-kernel
On Tue, Nov 06, 2012 at 09:49:50PM +0800, Shawn Guo wrote:
On Tue, Nov 06, 2012 at 10:12:29AM +0000, Russell King - ARM Linux wrote:quoted
quoted
[ 0.000000] sched_clock: 16 bits at 32kHz, resolution 31250ns, wraps every 20 47msSo where are you setting this up? My guess is it's after time_init() has done its stuff.It gets set up in machine_desc->timer->init() which is called right in time_init() just before sched_clock_postinit().
Well. I just tried an experiment with OMAP4: [ 0.000000] sched_clock: 16 bits at 32kHz, resolution 30517ns, wraps every 1999ms So, this is similar to yours, and there I get: [ 1.945281] ALSA device list: [ 1.948394] #0: SDP4430 [ 1.951324] Waiting 2sec before mounting root device... [ 2.926910] kjournald starting. Commit interval 5 seconds [ 2.927001] EXT3-fs (mmcblk1p2): warning: maximal mount count reached, running e2fsck is recommended [ 3.041503] EXT3-fs (mmcblk1p2): using internal journal [ 3.051422] EXT3-fs (mmcblk1p2): recovery complete [ 3.056427] EXT3-fs (mmcblk1p2): mounted filesystem with writeback data mode [ 3.063842] VFS: Mounted root (ext3 filesystem) on device 179:26. [ 3.070404] Freeing init memory: 192K So it appears to be working as designed.